The present invention relates to a light-weight bearing device having a housing made of synthetic resin.
A bearing device is composed of an outer sleeve, a housing into which the outer sleeve is inserted and a shaft inserted into the outer sleeve so that the housing with the outer sleeve is slidable in a linear fashion relative to the shaft. In particular, in a certain type of bearing device in which centering plates made of metal for performing automatic centering of the outer sleeve by a fine motion is provided, the outer sleeve is made of synthetic resin and the housing is made of metal (stainless steel in many cases).
The reason for this is as follows: Since an outward load is imposed to the centering plate provided on the outer sleeve by the contact of balls with the shaft when the housing with the outer sleeve is slidably moved in the linear fashion, if the housing would be made of synthetic resin, the contact portions between the housing and the centering plates would be worn and deformed so that there would be a fear that the outer sleeve and the housing would not come into intimate contact with each other with a rattle.
However, if the housing is made of synthetic resin, it is possible to considerably reduce the weight of the housing with the outer sleeve. In addition, it is advantageous to considerably enhance the productivity since the housing molding may be performed in an integral manner with molds.